What is Q345R?
It's a pressure vessel steel, with the same strength grade but lower S/P (Salt/Potential), stricter impact resistance, and higher flaw detection requirements. It's used in boilers/steam drums/storage tanks.
Applicable Scenarios?
Building steel beams/columns, bridges, cranes, vehicle chassis, ship structures, pressure vessels, mining machinery, wind turbine towers.
Can it be used in low-temperature environments?
Grade C ≥ 0℃, Grade D ≥ -20℃, Grade E ≥ -40℃ can be used directly; Grades A/B are not suitable for low temperatures.
How is its weldability?
Excellent, low carbon equivalent (Ceq≈0.42%), suitable for manual arc welding with E50 series electrodes, no preheating required (for thin parts).
Is it prone to cracking during welding?
For thick parts (>25mm) or low-temperature welding, preheating to 80–120℃ is required to prevent cold cracking; excessive S/P can easily lead to hot cracking.